1. Technical Field
The present invention relates to liquid supply units to be attached to carriage units of liquid ejection apparatuses.
2. Related Art
Printers have been widely used as a kind of liquid ejection apparatuses, and ink cartridges are used as liquid supply units for the printers. Hitherto, various engagement mechanisms for attaching and detaching the ink cartridges to/from the printers have been proposed. For example, a technique of providing a lever serving as the engagement mechanism on a side wall of an ink cartridge is known (JP-A-2007-230249). In this known technique, upon attaching the ink cartridge to a holder, the lever of the ink cartridge engages with an engaging portion of the holder and fixed. At the time of detachment, the engagement between the ink cartridge and the engaging portion is cancelled by a user pressing the lever, and the ink cartridge can be detached from the holder. A technique of providing a lever serving as an engagement mechanism in a holder on a carriage of a printer is also known (JP-A-2013-141804). In this known technique, upon attaching the ink cartridge to a holder, an engaging portion of the ink cartridge engages with the lever of the holder and fixed. At the time of detachment, the engagement between the ink cartridge and the lever is cancelled by a user pressing the lever, and the ink cartridge can be detached from the holder.
If the size of the lever is further reduced similarly to a reduction in size of ink cartridges, there is a possibility that the operability of the lever is lost. For this reason, there has been difficulty in providing a lever such as one described in JP-A-2007-230249 on a side wall of an ink cartridge in some cases. Meanwhile, even if a lever is provided in a holder on a carriage of a printer as in JP-A-2013-141804, there has been cases where a user feels difficulty in correctly recognizing the position at which the user presses the lever, or correctly pressing the lever, since the lever has been becoming smaller and smaller with the reduction in size of ink cartridges. For this reason, provision of a new engagement mechanism that does not exist in known techniques has been demanded. This problem is not limited to the ink cartridges for printers, but is also a problem shared by liquid supply systems for other kinds of liquid ejection apparatuses.